This invention relates to novel 2,5-dialkyl dihydrofuranones and 2,4,5-trialkyl dihydrofuranones having the structures: ##STR3## and mixtures of 2,5-dialkyl dihydrofuranones and 2,4,5-trialkyl dihydrofuranones having the structures: ##STR4## and the uses thereof in foodstuffs and foodstuff flavorings, chewing gums and toothpastes having sweet, brown sugar, pineapple-like, caramel, buttery, scorched butter-like, dried hazelnut and earthy aromas, and sweet, brown sugar-like, pineapple-like, caramel, buttery, cheese-like, roasted, vanilla-like, dried hazelnut and earthy tastes and has for an object the provision of a composition and process for improving the flavor and aroma of foodstuffs.
There has been considerable work performed relating to substances which can be used to impart (or enhance) flavors to (or in) various foodstuffs, chewing gums and toothpastes. These substances are used to diminish natural materials, some of which may be in short supply, and to provide more uniform properties in the finished product. Sweet, brown sugar, pineapple-like, caramel, buttery, scorched butter-like, dried hazelnut and earthy aromas, and sweet, brown sugar-like, pineapple-like, caramel, buttery, cheese-like, roasted, vanilla-like, dried hazelnut and earthy tastes are desirable for many uses in foodstuff flavors, chewing gum flavors and toothpaste flavors as well as foodstuffs per se, chewing gums per se and toothpastes per se, for example, maple, caramel, vanilla, butterscotch, rum, dairy, cereal, pineapple, roasted almond, and mushroom flavored foodstuffs.
German Offenlengungsschrift No. 2,359,891, published on June 6, 1974 entitled "2-alkyl-3(2H)-furanones" discloses the use of individual compounds having the generic structure: ##STR5## wherein R.sub.1 ' is hydrogen, hydroxyl, carboxyclic acid, or carboxylic acid ester and wherein R.sub.2 ' is C.sub.1 -C.sub.4 alkyl and wherein R.sub.3 ' is hydrogen, or C.sub.1 -C.sub.7 alkyl for use in foodstuffs and foodstuff flavors. The specific compound having the structure: ##STR6## is also disclosed in said German Offenlengungsschrift No. 2,359,891. However, the compounds which are novel of our invention having the structures: ##STR7## and the mixtures of our invention containing the compounds: ##STR8## have aroma and flavor intensities and substantivities which are significantly greater than and improved over the compounds of Offenlengungsschrift No. 2,359,891; and are so unexpectedly advantageous in quality of aroma that these compounds and mixtures represent an advance in the art over the disclosure of German Offenlengungsschrift No. 2,359,891. Furthermore, the compounds of the instant case which are novel having the structures: ##STR9## and the mixture of the four compounds having the structures: ##STR10## cannot be prepared by any process but that disclosed in the instant application. In addition, the processes set forth in Offenlengungsschrift No. 2,359,891 cannot be used to prepare the novel compounds of our invention or for that matter the mixtures of our invention.
The compounds of our invention and the mixtures of 2,5-dialkyl dihydrofuranones and 2,4,5-trialkyl dihydrofuranones of our invention, which 2,5-dialkyl dihydrofuranones and 2,4,5-trialkyl dihydrofuranones have the structures: ##STR11## can be prepared according to a process as described in U.S. Pat. No. 3,980,675. However, said process described in U.S. Pat. No. 3,980,675 is limited to the production of 2,5-dimethyl-3-(2H) furanone having the structure: ##STR12## and there is no suggestion concerning a method which can be used to prepare the compounds useful in our invention or the mixtures of the four compounds of our invention. Thus, whereas the process of U.S. Pat. No. 3,980,675 is limited to dimerization of the compound diacetyl followed by hydrolysis in acid media according to the reaction sequence ##STR13## the process of our invention is embodied in the reaction sequence ##STR14##
Accordingly, the process of our invention also represents an advance in the art over the process of U.S. Pat. No. 3,980,675.